Pros and cons - DIY step-by-step installation under the house + Video

The screw-pile foundation is one of the best in the construction of not very heavy structures, great for frame houses ... To understand all the pros and cons of this type of foundation, let's take a closer look at it.

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Screw piles for construction

Screw piles time-tested

The pile-screw type of foundation has been used in the world for about 300 years, they began to use it in the construction of lighthouses, a good example is the Sukhumi lighthouse, which survived the war perfectly and is still standing, which speaks of excellent reliability of this type of foundation.

For those who doubt that the piles rust and this type of foundation may be unreliable, here is the pile that was replaced at the ancient lighthouse, this pile is more than 300 years old, as you can see, it is perfectly preserved.

However, the most popular type of foundation in our the country is a strip flood foundation, but not every site can be arranged, and it is not cheap. There are clay soils with a high level of groundwater; on such land plots, the construction of a strip foundation is impossible. Then the technology of installing an above-ground type of buildings on a pile-screw foundation comes to the rescue. This type of foundations is also gaining popularity in our country due to its many advantages.

Main characteristics

Advantages of the pile-screw foundation

1. The main advantage is that the pile-screw foundation does not require a large amount of land work.
2. The technology of its construction is quite simple.
3. Installation speed and erection efficiency. In an hour on ordinary land, you can install a dozen piles, if you can try all fifteen.
4. In addition, its low cost is noted.

5. Ability to withstand decent loads and durability.
6. Any soil is suitable, except for rocks.
7. The use of special equipment is not necessary, the ability to install piles manually.
8. There is no need to wait after pouring the concrete, you can safely continue the construction of your house.
9. No vibration or noise during installation
10. Piles can be reused
11. The foundation for your frame house can always be extended.

12. Suitable for installation on slopes and uneven ground.

Disadvantages of screw piles

The disadvantages are actually not so obvious, especially for a small frame house construction, this type of foundation is ideal.

But still there are disadvantages:

1. Impossibility of erection on rocks or soils with a lot of stones in the soil.
2. Suitable for light frame and timber structures up to 3-4 floors.
3. Houses should have a sufficiently wide base.

4. When screwing in, the anti-corrosion coating is often damaged, which accelerates the corrosion of the metal.
5. Poor quality manufacturers.

It is also noted that the service life of the pile-screw foundation, although it is quite long, is still somewhat less than that of the concrete one. The service life of such a foundation can also be reduced by the damage that piles sometimes receive during the process of screwing into the ground. Piles with a damaged outer protective layer are more susceptible to corrosion.

Although the pile-screw foundation is well suited for private construction, it is better not to use it for the construction of heavy massive multi-storey buildings.

In addition, there are several more problems that can be encountered when organizing construction on a pile-screw foundation. First of all, you should know that the floor in the house on a pile-screw foundation will require additional insulation. It also often happens that the piles shrink unevenly during the operation of the house, and over time they generally get loose, if not done according to technology.

Therefore, in spite of its strength, the pile-screw foundation is welcomed in small-sized construction of frame houses, as well as in the construction of baths, garages and small outbuildings or decorative buildings on the site.

Screw piles. Design Features

In essence, screw piles are ordinary thick pipes with a screw-thread on the base. When screwed into the soil, the thread compresses it and fixes the pile firmly in the soil.

Dimensions and load capacity

Piles for pile-screw foundations are produced with a diameter of 100 to 300 mm and a length of up to 2.5 meters.

Such a pile can withstand from 4 to 8 tons each, the required length must be determined depending on the depth of soil freezing at the construction site , since a prerequisite is screwing the piles below this level (on average in Russia it is 1.5 m).

Extension of piles

If it is necessary to drive piles to a depth of more than 2.5 m, it is possible to extend them, this is provided for by their design.

The upper part of the pipe is closed with metal heads, popularly called "heels".

The service life of screw piles

The outer surface of the piles is covered with an anti-corrosion compound, so their service life under warranty is 50 years, in fact - much longer.

The inside of the pipe is recommended to be filled with concrete, this will protect the pile from destruction from the inside.

Calculation and installation of the pile-screw foundation

Based on the fact that even the piles of not the largest diameter have sufficient bearing capacity, their installation along the perimeter of the structure is considered optimal, under bearing walls and at their joints at a distance of 2-3 m.You should also determine the depth of their installation based on such a parameter as soil freezing in winter.

Layout of the pile field

The places where the piles are screwed into the soil are preliminarily marked with pegs, guided by the plan of the future structure.

Screwing in piles with your own hands

When screwing in piles, which, by the way, may well be done by several workers with their own hands using a lever, you should control the even vertical position of the pile relative to the horizon. The wider the pile diameter, the more difficult screwing will be. Of course, it is necessary to use a lever, it is inserted into the upper hole of the pile, the wider you make the lever, the less effort you apply, it is recommended to make a lever of 2-3 meters.

Piles are always screwed in below freezing of the soil, the average value in Russia is 1.3-1.

5 meters. At the end, the pile reaches hard soils and it is very difficult for the pile to enter the soil, almost impossible.

Twisting piles using special equipment

Also, if the construction budget allows or there is not enough labor, you can use the services of special equipment.

Leveling the pile foundation under the level

After all the piles are installed in the ground, the pile-screw foundation, like any other, is checked and leveled. It is most convenient to do this with a hydraulic level or nevilyr.

If necessary, the piles are tightened or cut off the protruding part with a grinder.

Pouring the piles with concrete

After alignment, the concrete mixture is poured inside the piles, which is designed to protect x from corrosion from the inside.

Installation of the grillage on the screw-pile foundation

At the final stage, the grillage is mounted, that is, the very foundation for the future house. For lighter construction, for example, a house made of timber or logs, it is possible to install a grillage from a thick bar. For houses made of bricks or blocks, it is better to make the grillage reinforced concrete.

The pile-screw foundation will not require time to shrink, the construction of the house can be continued immediately after installation of grillage. Now you can start installing the frame of your house. The foundation is ready for loading and full use.

Where to buy piles and what is the price?

Video twisting of screw piles